Big Brother
Ron spent his entire life wanting to be like Bill. He would follow his brother around the burrow, copying him, reciting his slang, he even learned how to play chess because Bill played chess.
Ron saw Bill as the perfect hero, big and broad, smart beyond all belief, always looking out for his younger brothers and sister. Bill never got fed up with him like Charlie did, or called him slow when he didn't understand a new home schooling subject like Percy. He never excluded him like the twins. Bill was perfect.
When Ron got to Hogwarts, he tried so hard to be like Bill. He tried to work hard like Bill had, but the twins would make fun of him. What did it matter anyway? He would never get the highest marks like his brother, not with Granger around. He would never be the one in the spotlight, not like Harry. But he could be the most loyal. Bill was always good for that. He could take care of Harry like Bill took care of him. He could stand up for Hermione against the jerk, Draco Malfoy, like Bill stood up against the twins. Ron could do that.
When Bill came home after Ron's fifth year, Ron felt ashamed. He was now the boy that let his little sister get hurt from his own foolishness. If he hadn't summoned that brain, he could have protected Ginny. Bill would have protected Ginny. Bill would have never made that mistake. Ron was never going to be like, Bill, and now he had the scars to prove it.
When Bill woke up in the Hospital Wing, all he could remember was pain and hunger. He felt Fleur by his side, and heard his mother's voice fluttering overhead, her tone full of worry. But when he opened his eyes, saw was his baby brother. His baby brother who had done more in his 17 years than Bill could ever hope to achieve. Who was brave, and loyal, and self sacrificing.
When he looked into Ron's eyes he could still see that hint of hero worship that Ron had worn plainly as a kid. The look that made Bill feel like he was on top of the world, that gave him a reason to keep working hard, and coming home, and doing everything he could to provide for his family. It was a look that he couldn't believe still sat in Ron's eyes, especially because all of those things he knew Ron looked up to in him, he now emulated from Ron himself.
'We match.' Bill tells Ron, tracing the scars along the boy's arms with his eyes.
'Hardly. Mine were a mistake. Yours were an attack.' Ron replies, looking down at his shoes. He hears his mother gasp in disbelief at Ron's answer, and Bill can't help but agree with her incredulity.
'Hey.' he calls Ron's attention back to him. 'Yours were an attack too. One you took protecting protecting Luna and Neville, Harry and Hermione. You took that attack to protect Ginny. Never believe otherwise. You are twice the man i am. Don't you ever forget that. Now chin up, and stop looking at me like i've grown a second head. you're gonna make me think i'm disfigured or something.' he chuckles, Ron joining in.
Fleur and his mother are not amused.